This invention pertains to the general field of jet-powered watercraft. Specifically, the invention relates to a method and device for monitoring oil level and condition in the jet propulsion system.
Water jet propulsion systems are becoming increasingly popular. Many skiers, fishers and family boaters realize that water jet propelled craft offer safety, simplicity and diverse utility. The propulsive force of the water jet transfers directly into the water without going through gears, right-angle shafts, or clutches. This translates into less weight, lower cost, lower maintenance and more reliability when compared to standard marine propeller drives. Functionally, a water jet propulsion system, or marine jet drive, is simply a propeller inside a pipe. The propeller operates as a pump impeller or rotor. The propulsion water intake port is typically an opening near the bottom of the hull, which picks up water and delivers it to the jet pump impeller. A grill across the intake port prevents foreign matter from entering the system. Water jet propulsion systems are also available in outboard engine packages for water craft. Simply stated, all marine jet drives function by inhaling water, compressing it, and passing it out a nozzle in the stern. The result is a powerful jet of water that pushes the vessel forward in the water. A water jet propulsion system can operate in just inches of water, as there is no external propeller. Jet driven water craft can skim flats, thread treacherous rocky passages and navigate river shoals. However, a need exists for the monitoring of the oil level and condition to enhance long-term performance of the water jet propulsion system. With this information, a water craft operator could approach, or even exceed, the advertised service life of the water jet propulsion system.
Current thrust cones are made of a nontransparent material. Consequently, troubleshooting is more complicated and time consuming, and can result in unnecessary disassembling of the water jet propulsion system, simply to check the oil level and condition.
The prior technology is deficient in that it requires the user to physically disassemble the jet pump housing in order to check the condition and level of the oil. When this procedure is performed the oil is now exposed to contaminate and should not be reused, which causes further unnecessary expense. Also, there are additional associated expenses with this procedure. This procedure is time consuming and should be performed by a qualified technician. One never knows the condition or level of the oil in the water jet propulsion system without removing the thrust cone. If this inspection is not performed periodically a catastrophic bearing failure can occur in the water jet propulsion system at a very high cost.